lib/sort: Add priv pointer to swap function

Adding support to have priv pointer in swap callback function.

Following the initial change on cmp callback functions [1]
and adding SWAP_WRAPPER macro to identify sort call of sort_r.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/bpf/20220316122419.933957-2-jolsa@kernel.org
[1] 4333fb96ca10 ("media: lib/sort.c: implement sort() variant taking context argument")

diff --git a/include/linux/sort.h b/include/linux/sort.h
index b589872..e163287 100644 (file)
--- a/include/linux/sort.h
+++ b/include/linux/sort.h
@@ -6,7 +6,7 @@
 
 void sort_r(void *base, size_t num, size_t size,
            cmp_r_func_t cmp_func,
-           swap_func_t swap_func,
+           swap_r_func_t swap_func,
            const void *priv);
 
 void sort(void *base, size_t num, size_t size,

diff --git a/include/linux/types.h b/include/linux/types.h
index ac825ad..ea8cf60 100644 (file)
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -226,6 +226,7 @@ struct callback_head {
 typedef void (*rcu_callback_t)(struct rcu_head *head);
 typedef void (*call_rcu_func_t)(struct rcu_head *head, rcu_callback_t func);
 
+typedef void (*swap_r_func_t)(void *a, void *b, int size, const void *priv);
 typedef void (*swap_func_t)(void *a, void *b, int size);
 
 typedef int (*cmp_r_func_t)(const void *a, const void *b, const void *priv);

diff --git a/lib/sort.c b/lib/sort.c
index aa18153..b399bf1 100644 (file)
--- a/lib/sort.c
+++ b/lib/sort.c
@@ -122,16 +122,27 @@ static void swap_bytes(void *a, void *b, size_t n)
  * a pointer, but small integers make for the smallest compare
  * instructions.
  */
-#define SWAP_WORDS_64 (swap_func_t)0
-#define SWAP_WORDS_32 (swap_func_t)1
-#define SWAP_BYTES    (swap_func_t)2
+#define SWAP_WORDS_64 (swap_r_func_t)0
+#define SWAP_WORDS_32 (swap_r_func_t)1
+#define SWAP_BYTES    (swap_r_func_t)2
+#define SWAP_WRAPPER  (swap_r_func_t)3
+
+struct wrapper {
+       cmp_func_t cmp;
+       swap_func_t swap;
+};
 
 /*
  * The function pointer is last to make tail calls most efficient if the
  * compiler decides not to inline this function.
  */
-static void do_swap(void *a, void *b, size_t size, swap_func_t swap_func)
+static void do_swap(void *a, void *b, size_t size, swap_r_func_t swap_func, const void *priv)
 {
+       if (swap_func == SWAP_WRAPPER) {
+               ((const struct wrapper *)priv)->swap(a, b, (int)size);
+               return;
+       }
+
        if (swap_func == SWAP_WORDS_64)
                swap_words_64(a, b, size);
        else if (swap_func == SWAP_WORDS_32)
@@ -139,7 +150,7 @@ static void do_swap(void *a, void *b, size_t size, swap_func_t swap_func)
        else if (swap_func == SWAP_BYTES)
                swap_bytes(a, b, size);
        else
-               swap_func(a, b, (int)size);
+               swap_func(a, b, (int)size, priv);
 }
 
 #define _CMP_WRAPPER ((cmp_r_func_t)0L)
@@ -147,7 +158,7 @@ static void do_swap(void *a, void *b, size_t size, swap_func_t swap_func)
 static int do_cmp(const void *a, const void *b, cmp_r_func_t cmp, const void *priv)
 {
        if (cmp == _CMP_WRAPPER)
-               return ((cmp_func_t)(priv))(a, b);
+               return ((const struct wrapper *)priv)->cmp(a, b);
        return cmp(a, b, priv);
 }
 
@@ -198,7 +209,7 @@ static size_t parent(size_t i, unsigned int lsbit, size_t size)
  */
 void sort_r(void *base, size_t num, size_t size,
            cmp_r_func_t cmp_func,
-           swap_func_t swap_func,
+           swap_r_func_t swap_func,
            const void *priv)
 {
        /* pre-scale counters for performance */
@@ -208,6 +219,10 @@ void sort_r(void *base, size_t num, size_t size,
        if (!a)         /* num < 2 || size == 0 */
                return;
 
+       /* called from 'sort' without swap function, let's pick the default */
+       if (swap_func == SWAP_WRAPPER && !((struct wrapper *)priv)->swap)
+               swap_func = NULL;
+
        if (!swap_func) {
                if (is_aligned(base, size, 8))
                        swap_func = SWAP_WORDS_64;
@@ -230,7 +245,7 @@ void sort_r(void *base, size_t num, size_t size,
                if (a)                  /* Building heap: sift down --a */
                        a -= size;
                else if (n -= size)     /* Sorting: Extract root to --n */
-                       do_swap(base, base + n, size, swap_func);
+                       do_swap(base, base + n, size, swap_func, priv);
                else                    /* Sort complete */
                        break;
 
@@ -257,7 +272,7 @@ void sort_r(void *base, size_t num, size_t size,
                c = b;                  /* Where "a" belongs */
                while (b != a) {        /* Shift it into place */
                        b = parent(b, lsbit, size);
-                       do_swap(base + b, base + c, size, swap_func);
+                       do_swap(base + b, base + c, size, swap_func, priv);
                }
        }
 }
@@ -267,6 +282,11 @@ void sort(void *base, size_t num, size_t size,
          cmp_func_t cmp_func,
          swap_func_t swap_func)
 {
-       return sort_r(base, num, size, _CMP_WRAPPER, swap_func, cmp_func);
+       struct wrapper w = {
+               .cmp  = cmp_func,
+               .swap = swap_func,
+       };
+
+       return sort_r(base, num, size, _CMP_WRAPPER, SWAP_WRAPPER, &w);
 }
 EXPORT_SYMBOL(sort);